pandas时间序列之pd.to_datetime()的实现

pd.to_datetime(
    arg,#int, float, str, datetime, list, tuple, 1-d array, Series DataFrame/dict-like
    errors='raise',# {'ignore', 'raise', 'coerce'}, default 'raise'
    dayfirst=False,
    yearfirst=False,
    utc=None,
    format=None,#格式，比如 "%d/%m/%Y"
    exact=True,
    unit=None,#单位str, default 'ns'，可以是(D,s,ms,us,ns)
    infer_datetime_format=False,
    origin='unix',#指定从什么时间开始，默认为19700101
    cache=True,
)

import datetime
import pandas as pd
import numpy as np
dti = pd.to_datetime(['1/1/2018', np.datetime64('2018-01-01'),
                      datetime.datetime(2018, 1, 1)])
dti

pd.to_datetime(['2020-04-20', '20/04/2020','Apr 20 2020'])

import time
time.asctime()

pd.to_datetime(time.asctime())

pd.to_datetime('20201111000000')

pd.to_datetime('2020/12/12', format='%Y/%m/%d')

pd.to_datetime('12-11-2010 00:00', format='%d-%m-%Y %H:%M')

df = pd.DataFrame({'year': [2015, 2016],
   ....:                    'month': [2, 3],
   ....:                    'day': [4, 5],
   ....:                    'hour': [2, 3]})
df

pd.to_datetime(df)

pd.to_datetime(df[['year','month','day']])

pd.to_datetime(['2009/07/31', 'asd'], errors='ignore')

pd.to_datetime(['2009/07/31', 'asd'], errors='raise')

pd.to_datetime(['2009/07/31', 'asd'], errors='coerce')

DatetimeIndex([‘1960-01-02', ‘1960-01-03', ‘1960-01-04'], dtype=‘datetime64[ns]', freq=None)

DatetimeIndex([‘1970-01-02', ‘1970-01-03', ‘1970-01-04'], dtype=‘datetime64[ns]', freq=None)